Electrical cable with optical fiber

ABSTRACT

An electrical cable includes a cable jacket extending a length and having an internal passageway that extends along the length of the cable jacket. Twisted pairs of insulated electrical conductors extend within the internal passageway along the length of the cable jacket. Each twisted pair includes two insulated conductors twisted together in a helical manner. At least two optical fibers extend within the internal passageway along the length of the cable jacket. The optical fibers are independently held within the internal passageway of the cable jacket relative to each other.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of application Ser. No. 14/216,035,filed Mar. 17, 2014, now U.S. Pat. No. 9,058,921, which is acontinuation of application Ser. No. 13/177,318, filed Jul. 6, 2011, nowU.S. Pat. No. 8,676,010, which applications are incorporated herein byreference in their entirety.

BACKGROUND OF THE INVENTION

The subject matter described and/or illustrated herein relates generallyto electrical cables.

Some known data communication cables include pairs of insulatedelectrical conductors that are twisted together to form a balancedtransmission line. Such pairs of insulated conductors are commonlyreferred to as “twisted pairs.” One example of a data communicationcable includes multiple twisted pairs that are bundled and twisted, orcabled, together and covered with a jacket.

It may sometimes be desirable to provide a secure electrical cable toprevent an unauthorized breech of the data being transmitted along theelectrical cable. For example, electrical cables used for many militaryand government communications are monitored and/or secured to preventthe cables from being tapped into by an unauthorized person or entity.But, known monitoring and/or securing methods for electrical cableshaving twisted pairs are not without disadvantages. One known method forsecuring electrical cables having twisted pairs includes enclosing theelectrical cable in a secure conduit that cannot be tapped into withoutconsiderable difficulty. However, enclosing electrical cables in such asecure conduit may be expensive, time-consuming, and/or difficult, forexample due to a required robustness of the secure conduit. A knownmethod for monitoring the security of an electrical cable having twistedpairs includes visually inspecting the cable along the length thereof todetermine if the cable has been tapped into. But, visually inspectingthe length of an electrical cable may take a considerable amount oftime, which may result in a delayed determination that the cable hasbeen breached. Moreover, the time-consuming nature of such visualinspection may be prone to operator error and/or may unnecessarily tieup worker capacity.

Accordingly, there is a need for an improved monitoring and/or securingelectrical cables having twisted pairs.

BRIEF DESCRIPTION OF THE INVENTION

In one embodiment, an electrical cable includes a cable jacket extendinga length and having an internal passageway that extends along the lengthof the cable jacket. Twisted pairs of insulated electrical conductorsextend within the internal passageway along the length of the cablejacket. Each twisted pair includes two insulated electrical conductorstwisted together in a helical manner. At least two optical fibers extendwithin the internal passageway along the length of the cable jacket. Theoptical fibers are independently held within the internal passageway ofthe cable jacket relative to each other.

In another embodiment, an electrical cable includes a cable jacketextending a length and having an internal passageway that extends alongthe length of the cable jacket. Twisted pairs of insulated electricalconductors extend within the internal passageway along the length of thecable jacket. Each twisted pair includes two insulated electricalconductors twisted together in a helical manner. At least one opticalfiber extends within the internal passageway along the length of thecable jacket. The at least one optical fiber is configured to sense adisturbance to the electrical cable.

In another embodiment, an electrical cable includes a cable jacketextending a length and having an internal passageway that extends alongthe length of the cable jacket. Electrical conductors extend within theinternal passageway along the length of the cable jacket. The electricalconductors are configured to conduct data signals. At least two opticalfibers extend within the internal passageway along the length of thecable jacket. The optical fibers are independently held within theinternal passageway of the cable jacket relative to each other.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross section of an exemplary embodiment of an electricalcable.

FIG. 2 is a cross-section of another exemplary embodiment of anelectrical cable.

FIG. 3 is a cross-section of another exemplary embodiment of anelectrical cable.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 is a cross section of the an exemplary embodiment of anelectrical cable 10. The cable 10 includes a central core 12, one ormore optical fibers 14 a and 14 b, and a jacket 16. Optionally, thecable 10 includes a rip cord 19 for exposing various internal componentsof the cable 10, for example to enable termination of such components.The cable 10 extends a length along a central longitudinal axis 20. Thejacket 16 extends around the central core 12 and the optical fibers 14 aand 14 b. More specifically, the jacket 16 extends a length along thelength of the cable 10 and includes an internal passageway 18 thatextends along the length of the jacket 16. The central core 12 and theoptical fibers 14 a and 14 b extend within the internal passageway 18 ofthe jacket 16 along the length of the jacket 16. As will be describedbelow, at least one of the optical fibers 14 a and/or 14 b is configuredto sense a disturbance to the electrical cable 10. The jacket 16 may bereferred to herein as a “cable jacket”.

The central core 12 includes a group of a plurality of twisted pairs 22of insulated electrical conductors 24. Alternatively, the cable 10includes a plurality of electrical conductors 24 that are not twistedinto twisted pairs. Each electrical conductor 24 is surrounded by aninsulative layer 28. Optionally, each of the twisted pairs 22 includesan electrical shield (not shown) that extends therearound. Theelectrical shield of each twisted pair 22 may be fabricated from anyelectrically conductive materials, structures, and/or the like, such as,but not limited to, an electrically conductive foil (e.g., a metal foiland/or the like), an electrically conductive tape (e.g., a metal tapeand/or the like), and/or the like. In some embodiments, the conductors24 of the twisted pairs are configured to conduct data signals. Thetwisted pairs 22 extend within the internal passageway 18 of the jacket16 along the length of the jacket 16. Optionally, the central core 12includes a binder element (not shown) that extends around the group oftwisted pairs 22 to hold the twisted pairs 22 together around thecentral longitudinal axis 20. The binder element is wrapped around thetwisted pairs 22 to thereby hold the twisted pairs 22 together in thegroup, with the binder element forming the radially-outermost (relativeto the central longitudinal axis 20) component of the central core 12.The binder element may be fabricated from any materials, structures,and/or the like, such as, but not limited to, a dielectric tape, anelectrically conductive material (e.g, an electrically conductive foil,an electrically conductive tape, and/or the like such as, but notlimited to, a metal foil, a metal tape, and/or the like), and/or thelike. When fabricated from an electrically conductive material, thebinder element may provide electrical shielding to the central core 12.The materials, structures, and/or the like of the binder element may beselected to comply with any applicable fire safety standards.

The two insulated conductors 24 of each twisted pair 22 are twistedtogether in a helical manner. In the exemplary embodiment of FIG. 1, thetwo insulated conductors 24 of each twisted pair 22 are twisted aroundeach other in a clockwise direction. The clockwise wrapping direction iscommonly referred to as a “right hand lay direction”. Alternatively, thetwo insulated conductors 24 of one or more of the twisted pairs 22 aretwisted around each other in a counter-clockwise direction. Thecounter-clockwise wrapping direction is commonly referred to as a “lefthand lay direction”.

Optionally, the twisted pairs 22 of the central core 12 extend alonghelical paths around the central longitudinal axis 20. In other words,each of the twisted pairs 22 is optionally wound into winding turns thatextend around the central longitudinal axis 20. Each twisted pair 22 maybe wrapped around the central longitudinal axis 20 in the clockwise orthe counter-clockwise direction. The winding turns of the twisted pairs22 may be interleaved between each other. In other embodiments, thetwisted pairs 22 extend along a path that is parallel to the centrallongitudinal axis 20 instead of a helical path. Although four twistedpairs 22 are shown, the central core 12 may include any number of thetwisted pairs 22.

In the exemplary embodiment of FIG. 1, the cable 10 includes two opticalfibers 14 a and 14 b. However, the cable 10 may include any number ofoptical fibers. In some embodiments, the cable 10 only includes a singleoptical fiber (e.g., the optical fiber 14 a or the optical fiber 14 b).The optical fibers 14 a and 14 b extend within the internal passageway18 of the jacket 16 along the length of the jacket 16. Each opticalfiber 14 a and 14 b consists of an optically transmissive strand 30,which is optionally coated with one or more insulation layers 32. Thestrand 30 may be fabricated from any optically transmissive material,such as, but not limited to, a glass, a polymer, a plastic, and/or thelike. In the exemplary embodiment of FIG. 1, each optical fiber 14 a and14 b consists of the strand 30 and a single insulation layer 32 coatedon the strand 30. Optionally, another insulation layer (not shown),which may be different from the insulation layer 32, is coated on theinsulation layer 32. The insulation layers 32 may be fabricated from anyinsulative materials, such as, but not limited to, a plastic, a polymer,polyvinyl chloride (PVC), fluorinated ethylene propylene (FEP),polyvinylidene fluoride (PVDF), polyethylene (PE) PE, and/or the like.Each optical fiber 14 a and 14 b may have any diameter, such as, but notlimited to, a diameter of between approximately 200 um and approximately1000 um. Each optical fiber 14 a and 14 b includes an outer surface(which is defined by an outermost insulation layer 32 if included) thatmay engage one or more of the twisted pairs 22. Each optical fiber 14 aand 14 b may be considered “sleeveless”.

The optical fibers 14 a and 14 b are independently held within theinternal passageway 18 of the jacket 16 relative to each other. By“independently held”, it is meant that the optical fibers 14 a and 14 bare not held within a common insulative sub-jacket (not shown) of thecable 10. In other words, optical fibers that are independently held arenot bundled together within a common jacket that extends within theinternal passageway 18 of the jacket 16.

As briefly described above, at least one of the optical fibers 14 aand/or 14 b is configured to sense a disturbance to the electrical cable10. More specifically, at least one of the optical fibers 14 a and/or 14b is configured to change the optical transmission characteristicsthereof in response to a mechanical disturbance to the electrical cable10. For example, at least one of the optical fibers 14 a and/or 14 b maybe configured to sense a disturbance to the electrical cable 10 bycommunicating an optical signal change along the optical fiber 14 aand/or 14 b, for example based on flexing of the optical fiber 14 aand/or 14 b when an attempt is made to cut into, grasp, pull on, lift,and/or the like the electrical cable. In the exemplary embodiment ofFIG. 1, each of the two optical fibers 14 a and 14 b is configured tosense a disturbance to the electrical cable 10. Alternatively, at leastone of the optical fibers 14 a and/or 14 b of the electrical cable 10 isused to transmit data signals, so long as at least one of the opticalfibers 14 a and/or 14 b of the cable 10 is configured to sense adisturbance to the cable 10.

Each of the optical fibers 14 a and 14 b may be positioned anywherewithin the internal passageway 18 of the jacket 16. In the exemplaryembodiment of FIG. 1, each optical fiber 14 a and 14 b extends betweenthe twisted pairs 22 of the central core 12. In other words, the opticalfibers 14 a and 14 b of FIG. 1 are positioned radially (relative to thecentral longitudinal axis 20) between the axis 20 and the twisted pairs22 such that the twisted pairs 22 extend around the optical fibers 14 aand 14 b. The optical fibers 14 a and 14 b therefore extend through thecentral core 12 in the exemplary embodiment of FIG. 1. The opticalfibers 14 a and 14 b may be arranged between the twisted pairs 22 in anyother pattern than is shown in FIG. 1. Optionally, the optical fibers 14a and 14 b are engaged with each other. The optical fibers 14 a and 14 bmay provide a central filler element between the twisted pairs, whichmay facilitate providing the cable 10 and/or the central core 12 with apredetermined shape (e.g., a circular cross-sectional shape). Thediameter, number of, and arrangement of the optical fibers 14 a and 14 bmay be selected to facilitate providing the cable 10 and/or the centralcore 12 with the predetermined shape.

The optical fibers 14 a and 14 b are optionally twisted around eachother in a helical manner, whether in the clockwise or counter-clockwisedirection. When twisted together, the twisted optical fibers 14 a and 14b may extend along a helical path (whether clockwise orcounter-clockwise) around the central longitudinal axis or may extendalong a path that is parallel to the central longitudinal axis 20instead of a helical path. When the optical fibers 14 a and 14 b are nottwisted together, each optical fiber 14 a and 14 b may extend along ahelical path around the central longitudinal axis 20 or may extend alonga path that is parallel to the central longitudinal axis 20 instead of ahelical path.

Optionally, the optical fibers 14 a and 14 b are optically connected toeach other. For example, ends (not shown) of the optical fibers 14 a and14 b may be optically connected to each other at an end (not shown) ofthe electrical cable 10. In the exemplary embodiment of FIG. 1, theoptical fibers include two discrete optical fibers 14 a and 14 b. In analternative embodiment, the optical fibers 14 a and 14 b representsegments of the length of the same optical fiber that are connectedtogether at a loop (not shown) of the optical fiber. In such analternative embodiment wherein the electrical cable 10 includes anoptical fiber having segments 14 a and 14 b that are connected togetherat a loop, the segments 14 a and 14 b are independently held within theinternal passageway 18 of the jacket 16.

The conductors 24 of the twisted pairs 22 may be fabricated from anyconductive materials, such as, but not limited to, bare copper, tinnedplated copper, silver plated copper, and/or the like. Each conductor 24may be formed from any number of strands of material. The insulativelayers 28 are fabricated from any insulative, non-conductive materials,such as, but not limited to, polypropylene, FEP,polytetrafluoroethylene-perfluoromethylvinylether (MFA), PE, and/or thelike. The jacket 16 may be fabricated from any at least partiallydielectric materials, such as, but not limited to, a polymer, PVC, lowsmoke zero halogen PVC, FEP, polyvinylidene fluoride (PVDF), PE, nylon,and/or the like. Optionally, the jacket 16 is formed using an extrusionprocess. In some embodiments, the jacket 16 is formed from a yarn, atape, and/or the like.

FIG. 2 is a cross section of another exemplary alternative embodiment ofan electrical cable 110. The cable 110 includes a central core 112, twooptical fibers 114 a and 114 b, an inner jacket 116, and an outer jacket121. The cable 110 includes optional rip cords 119 a and/or 119 b forexposing various internal components of the cable 110, for example toenable termination of such components. The cable 110 extends a lengthalong a central longitudinal axis 120. The inner jacket 116 extendsaround the central core 112 and one of the optical fibers 114 a. Theinner jacket 116 extends a length along the length of the cable 110 andincludes an internal passageway 118 that extends along the length of theinner jacket 116. The central core 112 and the optical fiber 114 aextend within the internal passageway 118 of the inner jacket 116 alongthe length of the inner jacket 116. The outer jacket 121 extends aroundthe inner jacket 116. More specifically, the outer jacket 121 includesan internal passageway 123 within which the inner jacket 116, thecentral core 112, and the optical fiber 114 a extend. Another of theoptical fibers 114 b extends between the inner and outer jackets 116 and121, respectively. The inner jacket 116 may be referred to herein as an“inner cable jacket”. The outer jacket 121 may be referred to herein asan “outer cable jacket”.

The central core 112 includes a group of a plurality of twisted pairs122 of insulated electrical conductors 124. Alternatively, the cable 110includes a plurality of electrical conductors 124 that are not twistedinto twisted pairs. Optionally, each of the twisted pairs 122 includesan electrical shield (not shown) that extends therearound. Theelectrical shield of each twisted pair 122 may be fabricated from anyelectrically conductive materials, structures, and/or the like, such as,but not limited to, an electrically conductive foil (e.g., a metal foiland/or the like), an electrically conductive tape (e.g., a metal tapeand/or the like), and/or the like. In some embodiments, the conductors124 of the twisted pairs 122 are configured to conduct data signals. Thetwisted pairs 122 extend within the internal passageway 118 of the innerjacket 116 such that the inner jacket 116 surrounds the twisted pairs122. Optionally, the central core 112 includes a binder element (notshown) that extends around the group of twisted pairs 122 to hold thetwisted pairs 122 together around the central longitudinal axis 120. Thebinder element is wrapped around the twisted pairs 122 to thereby holdthe twisted pairs 122 together in the group, with the binder elementforming the radially-outermost (relative to the central longitudinalaxis 120) component of the central core 112. The binder element may befabricated from any materials, structures, and/or the like, such as, butnot limited to, a dielectric tape, an electrically conductive material(e.g, an electrically conductive foil, an electrically conductive tape,and/or the like such as, but not limited to, a metal foil, a metal tape,and/or the like), and/or the like. When fabricated from an electricallyconductive material, the binder element may provide electrical shieldingto the central core 112. The materials, structures, and/or the like ofthe binder element may be selected to comply with any applicable firesafety standards. Although four twisted pairs 122 are shown, the centralcore 112 may include any number of the twisted pairs 122.

In the exemplary embodiment of FIG. 2, the cable 110 includes twooptical fibers 114 a and 114 b. However, the cable 110 may include anynumber of the optical fibers. The optical fibers 114 a and 114 b areindependently held within the internal passageway 123 of the outerjacket 121 relative to each other. By “independently held”, it is meantthat optical fibers 114 a and 114 b are not held within a commoninsulative sub-jacket (not shown) of the cable 110. In other words,optical fibers that are independently held are not bundled togetherwithin a common jacket that extends within the internal passageway 123of the outer jacket 121. In some embodiments, the cable 110 includesonly a single optical fiber 114 a or 114 b. Each optical fiber 114 a and114 b may be considered “sleeveless”.

In the exemplary embodiment of FIG. 2, the optical fiber 114 a extendswithin the internal passageway 118 of the inner jacket 116 along thelength of the jacket 116. The optical fiber 114 a extends between thetwisted pairs 122 of the central core 112. The optical fiber 114 a ispositioned radially (relative to the central longitudinal axis 120)between the axis 120 and the twisted pairs 122 such that the twistedpairs 122 extend around the optical fiber 114 a. The optical fiber 114 amay extend along a helical path around the central longitudinal axis 120or may extend along a path that is parallel to the central longitudinalaxis 120 instead of a helical path. The optical fiber 114 a may providea central filler element between the twisted pairs, which may facilitateproviding the cable 110 and/or the central core 112 with a predeterminedshape (e.g., a circular cross-sectional shape). The diameter, number of,and arrangement of the optical fiber 114 a may be selected to facilitateproviding the cable 110 and/or the central core 112 with thepredetermined shape. The optical fiber 114 a includes an outer surface(which is defined by an outermost insulation layer if included) that mayengage one or more of the twisted pairs 122.

The optical fiber 114 b extends between the inner and outer jackets 116and 121, respectively. More specifically, the optical fiber 114 b ispositioned radially (relative to the central longitudinal axis 120)between the inner and outer jackets 118 and 121, respectively. The outerjacket 121 surrounds the optical fiber 114 b, which extends around theinner jacket 116. The optical fiber 114 b may extend along a helicalpath around the inner jacket 116 (and around the central longitudinalaxis 120) or may extend along a path that is parallel to the centrallongitudinal axis 120 instead of a helical path. The optical fiber 114 bmay provide a spacing element that facilitates spacing the twisted pairs122 apart from neighboring electrical devices (e.g., the twisted pairsof a neighboring cable (not shown)). The diameter, number of, andarrangement of the optical fiber 114 b may be selected to facilitateproviding the cable 110 and/or the central core 112 with thepredetermined shape. The optical fiber 114 b includes an outer surface(which is defined by an outermost insulation layer if included) that mayengage the inner jacket 116 and/or the outer jacket 121.

At least one of the optical fibers 114 a and/or 114 b is configured tosense a disturbance to the electrical cable 110. More specifically, atleast one of the optical fibers 114 a and/or 114 b is configured tochange the optical transmission characteristics thereof in response to amechanical disturbance to the electrical cable 110. In some embodiments,at least one of the optical fibers 114 a and/or 114 b of the electricalcable 110 is used to transmit data signals.

Optionally, the optical fibers 114 a and 114 b are optically connectedto each other. For example, ends (not shown) of the optical fibers 114 aand 114 b may be optically connected to each other at an end (not shown)of the electrical cable 110. In the exemplary embodiment of FIG. 2, theoptical fibers include two discrete optical fibers 114 a and 114 b. Inan alternative embodiment, 114 a and 114 b represent segments of thelength of the same optical fiber that are connected together at a loop(not shown) of the optical fiber. In such an alternative embodimentwherein the electrical cable 110 includes an optical fiber havingsegments 114 a and 114 b that are connected together at a loop, thesegments 114 a and 114 b are independently held within the internalpassageway 123 of the outer jacket 121.

The inner and outer jackets 116 and 121, respectively, may each befabricated from any at least partially dielectric materials, such as,but not limited to, a polymer, PVC, low smoke zero halogen PVC, FEP,polyvinylidene fluoride (PVDF), PE, nylon, and/or the like. In someembodiments, the inner jacket 116 and/or the outer jacket 121 is formedusing an extrusion process. Moreover, in some embodiments, the innerjacket 116 and/or the outer jacket 121 is formed from a yarn, a tape,and/or the like. When formed from a yarn, tape, and/or the like, theinner jacket 116 and/or the outer jacket 121 may not be continuous alongthe length thereof, such that gaps extend within the jacket 116 and/or121 (for example between adjacent winding turns, or wraps, of the tape,yarn, and/or the like). If formed from a yarn, tape, and/or the like,any gaps within the outer jacket 121 may expose portions of the opticalfiber 114 b. When the outer jacket 121 is formed from a yarn, tape,and/or the like, the optical fiber 114 b may be considered to be“lashed” to the inner jacket 116 using the yarn, tape, and/or the likeof the outer jacket 121.

FIG. 3 is a cross section of another exemplary alternative embodiment ofan electrical cable 210. The cable 210 includes a central core 212, twooptical fibers 214 a and 214 b, an inner jacket 216, and an outer jacket221. The cable 210 includes optional rip cords 219 a and/or 219 b forexposing various internal components of the cable 210, for example toenable termination of such components. The cable 210 extends a lengthalong a central longitudinal axis 220. The inner jacket 216 extendsaround the central core 212. The inner jacket 216 includes an internalpassageway 218 within which the central core 212 extends. The outerjacket 221 extends around the inner jacket 216. The outer jacket 221includes an internal passageway 223 within which the optical fibers 214a and 214 b, the inner jacket 216, and the central core 212 extend. Theinner jacket 216 may be referred to herein as an “inner cable jacket”.The outer jacket 221 may be referred to herein as an “outer cablejacket”.

The central core 212 includes a group of a plurality of twisted pairs222 of insulated electrical conductors 224. Alternatively, the cable 210includes a plurality of electrical conductors 224 that are not twistedinto twisted pairs. Optionally, each of the twisted pairs 222 includesan electrical shield (not shown) that extends therearound. Theelectrical shield of each twisted pair 222 may be fabricated from anyelectrically conductive materials, structures, and/or the like, such as,but not limited to, an electrically conductive foil (e.g., a metal foiland/or the like), an electrically conductive tape (e.g., a metal tapeand/or the like), and/or the like. In some embodiments, the conductors224 of the twisted pairs 222 are configured to conduct data signals. Thetwisted pairs 222 extend within the internal passageway 218 of the innerjacket 216 such that the inner jacket 216 surrounds the twisted pairs222. Although four twisted pairs 222 are shown, the central core 212 mayinclude any number of the twisted pairs 222.

Optionally, the central core 212 includes a binder element (not shown)that extends around the group of twisted pairs 222 to hold the twistedpairs 222 together around the central longitudinal axis 220. The binderelement is wrapped around the twisted pairs 222 to thereby hold thetwisted pairs 222 together in the group, with the binder element formingthe radially-outermost (relative to the central longitudinal axis 220)component of the central core 212. The binder element may be fabricatedfrom any materials, structures, and/or the like, such as, but notlimited to, a dielectric tape, an electrically conductive material (e.g,an electrically conductive foil, an electrically conductive tape, and/orthe like such as, but not limited to, a metal foil, a metal tape, and/orthe like), and/or the like. When fabricated from an electricallyconductive material, the binder element may provide electrical shieldingto the central core 212. The materials, structures, and/or the like ofthe binder element may be selected to comply with any applicable firesafety standards. An optional central filler element 225 extends betweenthe twisted pairs 222. Optionally, the central filler element 225 isfabricated from a flat tape, such as, but not limited to, an aluminumtape, an aluminum/polyester tape, and/or the like.

Although two are shown, the cable 210 may include any number of theoptical fibers 214 a and 214 b. The cable 210 includes two opticalfibers 214 a and 214 b that are independently held within the internalpassageway 223 of the outer jacket 221 relative to each other. By“independently held”, it is meant that optical fibers 214 a and 214 bare not held within a common insulative sub jacket (not shown) of thecable 210. In other words, optical fibers that are independently heldare not bundled together within a common jacket that extends within theinternal passageway 223 of the outer jacket 221. In some embodiments,the cable 210 includes only a single optical fiber 214 a or 214 b. Eachoptical fiber 214 a and 214 b may be considered “sleeveless”.

The optical fibers 214 a and 214 b extend between the inner and outerjackets 216 and 221, respectively. More specifically, the optical fibers214 a and 214 b are each positioned radially (relative to the centrallongitudinal axis 220) between the inner and outer jackets 216 and 221,respectively. The outer jacket 221 surrounds the optical fibers 214 aand 214 b, which extend around the inner jacket 216. The optical fibers214 a and 214 b may each extend along a helical path around the innerjacket 216 (and around the central longitudinal axis 220) or may extendalong a path that is parallel to the central longitudinal axis 220instead of a helical path.

In the exemplary embodiment of FIG. 3, the optical fibers 214 a and 214b are arranged approximately 180° from each other about thecircumference of the inner jacket 216. However, the optical fibers 214 aand 214 b may be arranged between the inner jacket 216 and the outerjacket 221 in any other pattern than is shown in FIG. 3. For example, insome embodiments, the optical fiber 214 a is arranged approximately 90°from the optical fiber 214 b about the circumference of the inner jacket216. The optical fibers 214 a and 214 b may provide spacing elementsthat facilitates spacing the twisted pairs 222 apart from neighboringelectrical devices (e.g., the twisted pairs of a neighboring cable (notshown)). The diameter, number of, and arrangement of the optical fibers214 a and/or 214 b may be selected to facilitate providing the cable 210and/or the central core 212 with a predetermined shape (e.g., a circularcross-sectional shape). For example, in some embodiments, the cable 210includes four optical fibers arranged approximately 90° relative to eachother around the circumference of the inner jacket 216 to provide thecable 210 with a circular cross-sectional shape.

At least one of the optical fibers 214 a and/or 214 b is configured tosense a disturbance to the electrical cable 210. More specifically, atleast one of the optical fibers 214 a and/or 214 b is configured tochange the optical transmission characteristics thereof in response to amechanical disturbance to the electrical cable 210. In some embodiments,at least one of the optical fibers 214 a and/or 214 b of the electricalcable 210 is used to transmit data signals.

Optionally, the optical fibers 214 a and 214 b are optically connectedto each other. For example, ends (not shown) of the optical fibers 214 aand 214 b may be optically connected to each other at an end (not shown)of the electrical cable 210. In the exemplary embodiment of FIG. 3, theoptical fibers include two discrete optical fibers 214 a and 214 b. Inan alternative embodiment, 214 a and 214 b represent segments of thelength of the same optical fiber that are connected together at a loop(not shown) of the optical fiber. In such an alternative embodimentwherein the electrical cable 210 includes an optical fiber havingsegments 214 a and 214 b that are connected together at a loop, thesegments 214 a and 214 b are independently held within the internalpassageway 223 of the outer jacket 221.

The inner and outer jackets 216 and 221, respectively, may each befabricated from any at least partially dielectric materials, such as,but not limited to, a polymer, PVC, low smoke zero halogen PVC, FEP,polyvinylidene fluoride (PVDF), PE, nylon, and/or the like. In someembodiments, the inner jacket 216 and/or the outer jacket 221 is formedusing an extrusion process. Moreover, in some embodiments, the innerjacket 216 and/or the outer jacket 221 is formed from a yarn, a tape,and/or the like. When formed from a yarn, tape, and/or the like, theinner jacket 216 and/or the outer jacket 221 may not be continuous alongthe length thereof, such that gaps extend within the jacket 216 and/or221 (for example between adjacent winding turns, or wraps, of the tape,yarn, and/or the like). If formed from a yarn, tape, and/or the like,any gaps within the outer jacket 221 may expose portions of the opticalfibers 214 a and/or 214 b. When the outer jacket 221 is formed from ayarn, tape, and/or the like, the optical fibers 214 a and/or 214 b maybe considered to be “lashed” to the inner jacket 216 using the yam,tape, and/or the like of the outer jacket 221.

The embodiments described and/or illustrated herein may provide a secureelectrical cable. For example, the embodiments described and/orillustrated herein may provide an electrical cable having electricalconductors for conducting data signal and having an optical fiber formonitoring a security of the cable by sensing a disturbance to theelectrical cable. The embodiments described and/or illustrated hereinmay provide an electrical cable having twisted pairs for conducting datasignals and an optical fiber for monitoring a security of the cable bysensing a disturbance to the electrical cable, for example. Moreover,and for example, by using one or more optical fibers that areindependently held within a jacket of the cable, instead of beinggrouped under a common sub-jacket, the embodiments descried and/orillustrated herein may provide an electrical cable having bothelectrical conductors and optical fibers that is smaller than at leastsome known electrical cables.

In the above description, the cables 10, 110, and 210 are describedand/or illustrated in terms of premise cabling, such as, but not limitedto, a data communication cable and/or the like. However, it is to beunderstood that the subject matter described and/or illustrated hereinare also applicable to other types of cables, including, but not limitedto, wires, cords, cables, and/or the like of any type. The foregoingdescription and illustrations are therefore provided for illustrativepurposes only and are but one potential application of the subjectmatter described and/or illustrated herein.

It is to be understood that the above description is intended to beillustrative, and not restrictive. For example, the above-describedembodiments (and/or aspects thereof) may be used in combination witheach other. In addition, many modifications may be made to adapt aparticular situation or material to the teachings of the subject matterdescribed and/or illustrated herein without departing from its scope.Dimensions, types of materials, orientations of the various components,and the number and positions of the various components described and/orillustrated herein are intended to define parameters of certainembodiments, and are by no means limiting and are merely exemplaryembodiments. Many other embodiments and modifications within the spiritand scope of the claims will be apparent to those of skill in the artupon reviewing the above description and the drawings. The scope of thesubject matter described and/or illustrated herein should, therefore, bedetermined with reference to the appended claims, along with the fullscope of equivalents to which such claims are entitled. In the appendedclaims, the terms “including” and “in which” are used as theplain-English equivalents of the respective terms “comprising” and“wherein.” Moreover, in the following claims, the terms “first,”“second,” and “third,” etc. are used merely as labels, and are notintended to impose numerical requirements on their objects. Further, thelimitations of the following claims are not written inmeans—plus-function format and are not intended to be interpreted basedon 35 U.S.C. §112, sixth paragraph, unless and until such claimlimitations expressly use the phrase “means for” followed by a statementof function void of further structure.

What is claimed is:
 1. An electrical cable comprising: an outer cablejacket extending a length and having an internal passageway that extendsalong the length of the outer cable jacket; an inner cable jacketextending within the internal passageway of the outer jacket; twistedpairs of insulated electrical conductors extending within the internalpassageway along the length of the cable jacket, each twisted paircomprising two insulated electrical conductors twisted together in ahelical manner, the inner cable jacket surrounding the twisted pairs;and at least two optical fibers extending within the internal passagewayalong the length of the cable jacket, wherein the optical fibers areindependently held within the internal passageway of the cable jacketrelative to each other, the inner cable jacket surrounding a first ofthe optical fibers, a second of the optical fibers extending between theinner and outer jackets.
 2. The electrical cable of claim 1, wherein theoptical fibers are not held within a common sub jacket that extendswithin the internal passageway of the cable jacket.
 3. The electricalcable of claim 1, wherein outer surfaces of the first optical fiber areengaged with at least one of the twisted pairs.
 4. The electrical cableof claim 1, wherein the twisted pairs are configured to conduct datasignals.
 5. The electrical cable of claim 1, wherein the optical fibersare optically connected together.
 6. The electrical cable of claim 1,wherein at least one of the optical fibers comprises an insulativecoating.
 7. An electrical cable comprising: an outer cable jacketextending a length and having an internal passageway that extends alongthe length of the cable jacket; an inner cable jacket extending withinthe internal passageway and defining a central longitudinal axis;twisted pairs of insulated electrical conductors extending within theinternal passageway along the length of the outer cable jacket, eachtwisted pair comprising two insulated electrical conductors twistedtogether in a helical manner, the inner cable jacket surrounding thetwisted pairs; and at least one optical fiber extending within theinternal passageway between the inner and outer jackets along the lengthof the cable jacket, the at least one optical fiber being configured tosense a disturbance to the electrical cable.
 8. The electrical cable ofclaim 7, wherein the at least one optical fiber comprises first andsecond optical fibers, the inner cable jacket surrounding the twistedpairs and the first optical fiber, the second optical fiber extendingbetween the inner and outer jackets.
 9. The electrical cable of claim 8,wherein the first optical fiber is located within the internalpassageway between the twisted pairs.
 10. The electrical cable of claim9, wherein an outer surface of the second optical fiber is engaged withat least one of the twisted pairs.
 11. The electrical cable of claim 7,wherein the twisted pairs are configured to conduct data signals. 12.The electrical cable of claim 7, wherein the optical fiber comprises aninsulative coating.
 13. The electrical cable of claim 7, wherein the atleast one optical fiber is configured to sense the disturbance to theelectrical cable by communicating an optical signal change along the atleast one optical fiber.
 14. An electrical cable comprising: an outercable jacket extending a length and having an internal passageway thatextends along the length of the outer cable jacket; an inner cablejacket extending within the internal passageway; electrical conductorsextending within the internal passageway along the length of the cablejacket, the electrical conductors being configured to conduct datasignals; and at least two optical fibers extending within the internalpassageway between the inner and outer jackets along the length of thecable jacket and positioned radially relative to the centrallongitudinal axis, wherein the optical fibers are independently heldwithin the internal passageway of the cable jacket relative to eachother.
 15. The electrical cable of claim 14, wherein the optical fibersare not held within a common sub jacket that extends within the internalpassageway of the cable jacket.
 16. The electrical cable of claim 14,wherein the optical fibers each extend along a helical path around theinner jacket.
 17. The electrical cable of claim 14, wherein the opticalfibers each extend along a path that is parallel to the centrallongitudinal axis.
 18. The electrical cable of claim 14, wherein theoptical fibers are arranged approximately 180° from each other about acircumference of the inner jacket.